Problem: Simplify the following expression: $n = \dfrac{5k}{6} - \dfrac{k}{10}$
Solution: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $6$ and $10$ $\lcm(6, 10) = 30$ $ n = \dfrac{5}{5} \cdot \dfrac{5k}{6} - \dfrac{3}{3} \cdot \dfrac{k}{10} $ $n = \dfrac{25k}{30} - \dfrac{3k}{30}$ $n = \dfrac{25k -3k}{30}$ $n = \dfrac{22k}{30}$ Simplify the expression by dividing the numerator and denominator by 2: $n = \dfrac{11k}{15}$